Warning lights are commonly mounted on barrels or other structures in work zones and on construction sites, and are used in either flashing or steady-burn mode. For example, type A flashing warning lights are used to warn motorists of upcoming work zones or road hazards. Type C steady-burn lights are used to delineate a travel lane through and around a construction area.
Battery-powered warning lights are typically powered by two 6-volt batteries. Such lights may use incandescent light bulbs or, more recently, light emitting diodes (LEDs). LEDs consume less energy than incandescent bulbs. Warning lights using LEDs may have a higher initial cost, but are advantageous due to the reduced energy consumption.
Warning lights which use LEDs and which are powered by rechargeable batteries connected to solar panels are known. Such lights are available, for example, from Interplex Solar, Inc. of New Haven, Conn.
Rechargeable batteries may be damaged by low and high discharge rates. If a battery is discharged too low, the negative electrode may be oxidized. A nickel metal hydride (NiMH) negative electrode stores hydrogen during the charging process and releases hydrogen during discharge. A nickel cadmium (NiCad) negative electrode stores cadmium when receiving a charge and releases cadmium during discharge. These storage locations within the negative electrode are called activation sites. During overdischarge, oxygen will migrate into the negative electrode and permanently occupy these activation sites lowering the negative electrode's energy storage capability.
Lenses used with current Type A warning lights are round in shape. This shape is used, at least in part, to more evenly collect and disperse light generated by an incandescent light source. Incandescent light sources emit light spherically. The best way to capture the most light from such a light source is by use of a round lens. Round lenses have continued in use even with LED light sources, notwithstanding that LED light sources emit light axially, rather than spherically.
A need exists for addressing problems associated with degradation of rechargeable batteries, particularly rechargeable batteries which are connected to solar panels or cells. A need further exists to improve the design of lenses and/or reflectors on warning lights using LEDs.